Mechanically programmed soft actuators with conforming sleeves

ABSTRACT

A mechanically programmed actuator includes at least one soft actuator body configured to bend, linearly extend, contract, twist, or combinations thereof when actuated without constraint; an activation mechanism (e.g., a fluid pump) configured to actuate the soft actuator body; and at least one sleeve wrapped around part of the soft actuator body and configured to constrain the soft actuator body inside the sleeve when actuated and to cause the soft actuator body to deform where not covered by the sleeve.

GOVERNMENT SUPPORT

This invention was made with government support under Grant No.W911NF-11-1-0094 awarded by the Defense Advanced Research ProjectsAgency. The United States Government has certain rights in theinvention.

BACKGROUND

Soft actuators offer several desirable features not found in rigidmechanical systems including the ability to embed complex motions into amonolithic structure, and inherent compliance due to the elastomericmaterials and pressurized fluids. Computer-aided drafting (CAD) programsand three-dimensional (3D) printers allow relatively fast iteration ofmold designs for actuator fabrication (on the order of days); theseapproaches, however, may not allow for “on-the-fly” modification of asoft actuator's output motions, connection interfaces, and surfaceproperties. This capacity is advantageous where immediate customizationis needed, such as on the production floor for robotic manipulation orrehabilitation, where patient needs vary.

SUMMARY

Mechanically programmed soft actuators and methods for their fabricationand use are described herein. Various embodiments of the apparatus andmethods may include some or all of the elements, features and stepsdescribed below.

A mechanically programmed soft actuator includes at least one softactuator body where a least a portion of it is configured to bend,linearly extend, contract, twist or combinations thereof when actuatedwithout constraint; an activation mechanism (e.g., a fluid pump)configured to actuate the soft actuator body; and at least oneconforming sleeve wrapped around part of the soft actuator body andconfigured to constrain the soft actuator body inside the sleeve whenactuated and to cause the soft actuator body to bend where it is notcovered by the sleeve.

In a method for mechanical actuation, fluid (e.g., air or liquid) ispumped into a chamber defined by the soft actuator body, causing thesoft actuator body to bend where the soft actuator body is not coveredby the sleeve, while the sleeve constrains bending of the soft actuatorbody where the sleeve covers the soft actuator body.

Embodiments of these actuators can provide for safe human-robotinteraction, where soft tissues (e.g., skin) can interact with soft andcompliant robotic actuators to increase comfort and to reduce the riskof injury to the user. These soft actuators are suitable for a varietyof uses including use as robotic actuators to assist human movement, useas a conformable gripper for manipulating objects and use in toys (e.g.,as an interface for video games).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a photographic image of a curling soft actuator body 14without a sleeve.

FIG. 2 is a photographic image of the curling soft actuator body 14 ofFIG. 1 after a change in pressure in the actuator body 14.

FIG. 3 is a photographic image of the soft actuator body 14 of FIG. 1surrounded by sleeves 16 respectively at its base and at its remote end.

FIG. 4 is a photographic image of the actuator 12 of FIG. 3 after achange in pressure in the actuator body 14.

FIG. 5 is an illustration of a soft actuator body 14 with astrain-limiting layer 54 on its right side; an initial position of theactuator body 14 is shown at left, while the curl in the actuator body14 due to the strain-limiting layer 54 after a change in pressure in theactuator body 14 is shown at right.

FIG. 6 is an illustration of a soft actuator body 14 surrounded by asleeve 16 at its base and with a strain-limiting layer 54 on its rightside; an initial position of the actuator body 14 is shown at left,while the curl in the actuator body 14 due to the strain-limiting layer54 above the sleeve 16 after a change in pressure in the actuator body14 is shown at right.

FIG. 7 is an illustration of a soft actuator body 14 surrounded bysleeves 16 respectively at its base and at its remote end and with astrain-limiting layer 54 on its right side; an initial position of theactuator body 14 is shown at left, while the bend in the actuator body14 due to the strain-limiting layer 54 between the sleeves 16 after achange in pressure in the actuator body 14 is shown at right.

FIG. 8 shows a sleeve 16 thermoformed to a soft actuator body 14 via theapplication of heat.

FIG. 9 shows the soft actuator body 14 with the sleeve 16 thermoformedthereon.

FIG. 10 shows a sleeve 16 attached to a soft actuator body 14 via pinchclamps 24′ secured about the sleeve 16.

FIG. 11 shows a sleeve 16 attached to a soft actuator body 14 via zipties 24″ secured about the sleeve 16.

FIG. 12 shows a sleeve 16 secured to a soft actuator body 14 viarespective surfaces of hooks and loops 24′″ on the top side of one endof the sleeve 16 and on the bottom side of the opposite end of thesleeve 16.

FIG. 13 shows a sleeve 16 secured to a soft actuator body 14 via a lace24″″ threaded through apertures along each of the opposite ends of thesleeve 16.

FIG. 14 shows a sleeve 16 secured to a soft actuator body 14 via glue24′″″ inserted between the sleeve 16 and the soft actuator body 14.

FIG. 15 shows an actuator 12 with a plurality of joints formed betweenmore than two sleeves 16 spaced along the length of the actuator 12.

FIG. 16 shows the actuator 12 of FIG. 15 after a pressure change in thesoft actuator body 14, where the soft actuator body 14 bends between thesleeves 16.

FIG. 17 shows a variety of embodiments of actuators wherein the softactuator body 14 is covered by one, two or three sleeve sections 16 andwith the sleeves 16 extending different distances across the softactuator body 14.

FIG. 18 shows a sleeve 16 that can act as a mounting substrate forelectronics (e.g., a contact sensor 26 and a circuit board 28).

FIGS. 19 and 20 show a sleeve 16 that can act as an anchor point for asoft sensor, such as a strain gauge 30 (e.g., connecting via hooks andloops, sewn, glued, etc.).

FIGS. 21-24 show a sleeve 16 that can act as an interface to connectrigid devices to a soft connector (e.g., a scoop, lever, spring or anymechanism to be actuated); in this embodiment, the sleeve 16 includesthreaded posts 32 to serve as the interface.

FIGS. 25-27 show the integration or embedding of magnets 38 (e.g., tofacilitate alignment during grasping, for attaching tools, or for use inrapid collection of ferrous metal objects).

FIGS. 28 and 29 show the use of a sleeve 16 as a coupler to connectactuator bodies 14 in series.

FIGS. 30 and 31 show the use of sleeves 16 connected in parallel tocouple soft actuator bodies 14 together in parallel.

FIG. 32 shows the use of a sleeve 16 to join four soft actuator bodies14 into an “X-joint”.

FIG. 33 shows the use of a sleeve 16 to join three soft actuator bodies14 into an “T-joint”.

FIG. 34 shows the use of a sleeve 16 to join two soft actuator bodies 14end-to-end.

FIG. 35 shows brushes 44 extending from a surface of a sleeve 16.

FIG. 36 shows bumps 46 protruding on a surface of a sleeve 16.

FIG. 37 shows loops 48 (alternatively, or in addition, hooks can beprovided) on a surface of a sleeve 16.

FIG. 38 shows a sleeve 16 with perimeter channels 50 for routing tubesand wires to minimize snagging and tangling.

FIG. 39 shows the sleeve 16 of FIG. 38 with tubes and wires 52 fedthrough the perimeter channels 50 and with the sleeve 16 mounted on asoft actuator body 14.

FIGS. 40 and 41 show sleeve rings 16 that are narrow in width and spacedalong a connecting rigid strip to provide multiple bending positions forthe underlying soft actuator body 14.

FIGS. 42-44 show the bending of a soft actuator body 14 at sleevespacings of 0, 15, and 30 mm, respectively; the shadow images show theactuators bending at different pressures.

FIG. 45 shows a sleeve 16 with an aperture 22 to allow for bending of anunderlying soft actuator body at the aperture 22.

FIGS. 46-48 show a sleeve 16 with a plurality of apertures 22 positionedat different length-wise and azimuthal locations on the sleeve 16 toprovide for bending at different locations and about axes alongdiffering orientations (wherein the direction of bending is shown witharrows 23 in FIG. 48.

FIG. 49 shows a sleeve 16 with embedded electrical circuits and wiring62.

FIG. 50 shows a sleeve 16 that can connect a soft actuator 12 to a bodypart 63 (here, a finger).

FIG. 51 shows an attempt to grasp a square object 66 with a manipulatorincluding curling soft actuators 12 without sleeves.

FIG. 52 shows a manipulator with curling soft actuators 12 covered withsleeves 16 having a length matching that of a side of an object 66 to begrasped.

FIG. 53 shows the sleeved soft actuators 12 of the manipulator of FIG.52 grasping an object 66.

FIG. 54 shows soft actuator bodies 14 without sleeves supporting anobject 66 under load.

FIG. 55 shows soft actuators with sleeves 16 supporting an object 66under a greater load.

FIG. 56 shows soft actuators with sleeves 16 that have afiber-reinforced laminate structure supporting an object 66 with a stillgreater load.

FIGS. 57 and 58 show additional embodiments of soft actuator bodies 14grasping an object 66, respectively, with and without sleeves 16.

FIGS. 59 and 60 show a shape-matched manipulator with a sleeve 16 on acurling soft actuator body 14 and a second curling actuator without asleeve.

FIGS. 61-64 show a sleeve 16 that can be unrolled to provide anadjustable length of bending constraint on an underlying soft actuatorbody 14.

FIGS. 65-67 show a sleeve 16 that includes a segment that can beextended to provide an adjustable length of bending constraint on anunderlying soft actuator body 14.

FIGS. 68 and 69 show a soft actuator body 14 with the adjustable-lengthsleeves 16 of FIGS. 61 and 64 at both ends of the soft actuator body 14,showing that the bend radius of the soft actuator body 14 decreases asthe sleeves 16 are lengthened by further unrolling.

Illustrations (a)-(d) of FIG. 70 show a cross-sectional comparison of afiber-reinforced actuator body 14, with (c and d) and without (a and b)an inelastic (strain-limiting) fiber-reinforced laminate structure 54,where (a) shows an illustrated cross section and actual side view of anunpressurized fiber-reinforced actuator body 14; (b) shows expansion ofthe walls of the actuator body 14 due to fluid pressurization; (c)demonstrates placement of an inelastic fiber-reinforced laminate 54 on afiber-reinforced actuator body 14; and (d) shows an illustratedcross-section view of the actuator when a sleeve 16 is added.

Illustrations (a)-(c) of FIG. 71 show the range of motion of softbending actuators with inelastic fiber-reinforced laminates on theirflat surface with respective sleeve 16 spacings of (a) 0 mm, (b) 15 mm,and (c) 30 mm.

FIG. 72 shows an unactuated linearly extending soft actuator 12 with aninner and outer sleeve 16′ and 16″ with apertures 22 through bothsleeves 16 that serve as bending joints and a gap in the outer sleeve16″ that serves as an extension segment 70 where the inner sleeve 16′can longitudinally extend. The sleeves enable multi-segment motion

FIG. 73 shows the soft actuator 12 of FIG. 72 in an actuated state.

FIG. 74 is a photographic image of a linearly extending soft actuatorbody 14 contained in a sleeve 16 with an aperture in the form of a slitto generate bending of the actuator.

FIG. 75 is a photographic image of the linearly extending soft actuatorof FIG. 74 when actuated by fluid pumped into the soft actuator body 14.

FIG. 76 is a photographic image of a linearly extending soft actuatorbody 14 contained in a sleeve 16 with two apertures to generate bendingof the actuator at each aperture in opposite directions due to theorientation of the apertures.

FIG. 77 is a photographic image of a linearly extending soft actuatorcontained in a sleeve 16 with a plurality of apertures and uncutportions 69 of the sleeve 16 configured to generate bending of theactuator about a plurality of axes with different orientations.

FIG. 78 is a photographic image of a linearly extending soft actuatorconverted into a bending actuator by a sleeve 16 with uncut portions 69and a plurality of apertures that share a common orientation andconsistent spacing there between.

FIGS. 79 and 80 are photographic images of a power grip glove includinga curling soft actuator for each finger, wherein each actuator includesa linearly extending soft actuator contained in a sleeve 16 having aplurality of apertures to convert the linear actuation of the softactuator to a bending/curling motion.

FIG. 81 shows a soft actuator body 14 dispensed from a reel andseverable to produce the desired length.

FIG. 82 shows a cut segment of the soft actuator body 14 of FIG. 81 withcaps 68 inserted at each end and with a pneumatic or hydraulicconnection 60 in one of the end caps to enable the introduction of fluidinto the soft actuator body 14.

FIGS. 83-85 provide perspective views of a soft actuator body 14 with asleeve 16 at its distal end that includes gripping features 49.

FIGS. 86-88 illustrate embodiments of an actuator 12 with segments thatcan stiffen, which can therefore control deformation, via activation ofvacuum jamming pouches 80 mounted on the sleeve 16.

FIG. 89 illustrates an actuator 12 that includes a vacuum jamminggripper 82 mounted on the sleeve 16.

In the accompanying drawings, like reference characters refer to thesame or similar parts throughout the different views; and apostrophesare used to differentiate multiple instances of the same or similaritems sharing the same reference numeral. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingparticular principles, discussed below.

DETAILED DESCRIPTION

The foregoing and other features and advantages of various aspects ofthe invention(s) will be apparent from the following, more-particulardescription of various concepts and specific embodiments within thebroader bounds of the invention(s). Various aspects of the subjectmatter introduced above and discussed in greater detail below may beimplemented in any of numerous ways, as the subject matter is notlimited to any particular manner of implementation. Examples of specificimplementations and applications are provided primarily for illustrativepurposes.

Unless otherwise defined, used or characterized herein, terms that areused herein (including technical and scientific terms) are to beinterpreted as having a meaning that is consistent with their acceptedmeaning in the context of the relevant art and are not to be interpretedin an idealized or overly formal sense unless expressly so definedherein. For example, if a particular composition is referenced, thecomposition may be substantially, though not perfectly pure, aspractical and imperfect realities may apply; e.g., the potentialpresence of at least trace impurities (e.g., at less than 1 or 2%) canbe understood as being within the scope of the description; likewise, ifa particular shape is referenced, the shape is intended to includeimperfect variations from ideal shapes, e.g., due to manufacturingtolerances. Percentages or concentrations expressed herein can representeither by weight or by volume.

Although the terms, first, second, third, etc., may be used herein todescribe various elements, these elements are not to be limited by theseterms. These terms are simply used to distinguish one element fromanother. Thus, a first element, discussed below, could be termed asecond element without departing from the teachings of the exemplaryembodiments.

Spatially relative terms, such as “above,” “below,” “left,” “right,” “infront,” “behind,” and the like, may be used herein for ease ofdescription to describe the relationship of one element to anotherelement, as illustrated in the figures. It will be understood that thespatially relative terms, as well as the illustrated configurations, areintended to encompass different orientations of the apparatus in use oroperation in addition to the orientations described herein and depictedin the figures. For example, if the apparatus in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the exemplary term, “above,” may encompass both an orientation ofabove and below. The apparatus may be otherwise oriented (e.g., rotated90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

Further still, in this disclosure, when an element is referred to asbeing “on,” “connected to,” “coupled to,” “in contact with,” etc.,another element, it may be directly on, connected to, coupled to, or incontact with the other element or intervening elements may be presentunless otherwise specified.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting of exemplary embodiments.As used herein, singular forms, such as “a” and “an,” are intended toinclude the plural forms as well, unless the context indicatesotherwise. Additionally, the terms, “includes,” “including,” “comprises”and “comprising,” specify the presence of the stated elements or stepsbut do not preclude the presence or addition of one or more otherelements or steps.

The methods and actuator designs disclosed, herein, can put the power ofsoft actuator customization into the user's hands and can eliminate theneed to mold a new soft actuator to fit a particular application. Asdescribed herein, sleeves 16 can be used to mechanically program softactuators 12, which allows rapid modification (e.g., on the order ofminutes) of a soft actuator's motion and capabilities. As an example,FIGS. 1 and 2 show the motion of a curling soft actuator 12 whenactuated by an activation mechanism 18 (e.g., as a pump fills the softactuator body 14 with fluid). One means for generating the curlingmotion is to adhere a strain-limiting layer 54 that resists elastic orplastic deformation along its length (relative to unrestrained portionsof the soft actuator body 14), thereby causing curling of the actuator12, as shown in FIG. 5, when under stress (e.g., an increase in internalpressure). This motion can be adjusted by applying sleeves 16, such asshrink tubing, to the soft actuator body 14 and leaving a full orpartial opening where bending motion is desired, as shown in FIGS. 3 and4. Wrapping the soft actuator body 14 with such a sleeve 16 can convertthe soft curling actuator body 14 to a more-acutely bending actuator (orcan convert a linear actuator into a bending actuator, as discussedbelow and as shown in FIGS. 72-80) and can produce a distinctlydifferent motion (e.g., joint-like bending). The use of sleeves 16 alsoenables new opportunities to add a variety of features and capabilitiesto the soft actuator body 14, such as interfacing with sensors 26,electronics, mechanical tools, and other soft actuators and inclusion ofprinted circuit boards 28 mounted thereon (see, FIGS. 18-24, 35-39 and49). As shown in FIGS. 21 and 22, the sleeve can also include mounts 32(in the form of threaded posts in this embodiment) for mounting otherobjects 33 to the sleeve 16 or for mounting the sleeve 16 to otherstructures. As shown in FIGS. 23 and 24, the actuator 12 can be mountedto rigid links 34, which are joined at a pivot 36 to form an actuatingpivoting structure.

Soft actuator bodies 14 of this disclosure include walls that define achamber 20 that can be formed of, e.g., hyper-elastic silicone, thermoplastic elastomer, thermo plastic urethane, rubber, elasticpolyurethane, or polyethylene. Accordingly, the soft actuator body 14can be designed to expand its dimensions, e.g., to 200% of its originaldimensions before failure, while the sleeve 16 in which the softactuator body 14 is contained can be formed of a flexible, rigid, and/orelastomeric material (e.g., in the form of a non-expanding fabric with,for example, no more than 1/10th the elasticity of the soft actuatorbody 14), such that the sleeve 16 constrains the soft actuator body 14and such that the soft actuator body 14 presses against the sleeve 16when the soft actuator body 14 is expanded (e.g., by an increase ininternal pressure).

The combination of the soft actuator body 14 and constraining sleeve 16can include any or all of the following features. First, the sleeves 16can alter the motion of a soft actuator body 14. A single sleeve 16 canbe used to move the bending position anywhere along the length of thesoft actuator body 14 by limiting any part of the soft actuator body 14that is enclosed in the sleeve 16 from deforming, as shown in FIG. 6,and by promoting deformation at an aperture 22 (in the form, e.g. of aslit or a cut-out, as shown in FIG. 45) in the sleeve 16. In additionalembodiments, two sleeves 16 can be positioned and spaced apart to movethe bending position and to alter the actuator's radius of curvature tocreate joint-like bending, as shown in FIGS. 3, 4, and 7. Additionally,the sleeves 16 can be thermoformed; or secured with a securing mechanism24, such as pinch clamps 24′, laces 24″ (e.g., with cable ties), rubberbands 24′″, zip ties 24″″, inter-locking hook-and-loop structures 24″″′(e.g., VELCRO adhesive), or sewn thread; or rolled on thermally weldedon or glued to the soft actuator body 14, as shown in FIGS. 8-14. Inparticular embodiments where the soft actuator 12 is used for medicalapplications, both the soft actuator body 14 and the sleeve 16 can beformed of or coated with a biocompatible material, such as silicone orparylene polymer. .In additional embodiments, sleeves 16 can be cut todifferent lengths to change the location and bending radius of “joints”created in the soft actuator 12. Additionally, the sleeves 16 can bedesigned to be removable from the soft actuator body 14 to free the softactuator body 14 for re-use [e.g., the sleeves 16 can be cut off, slidoff, untied, pulled apart (particularly when hook and loop structuresare used), removed via the application of heat, etc.]

In still more embodiments, sleeves 16 can be used to create multiplejoints with different radii of curvature around multiple axes on asingle soft actuator body 14, as shown in FIGS. 15-17 and 46-48. Thesoft actuator body 14 does not necessarily have to contain astrain-limiting layer. Alternatively, the soft actuator body can be alinear extending soft actuator or any elastomeric bladder; and the uncutband of sleeve material behind the aperture 22 can perform the functionof the strain-limiting layer 54, as shown in FIGS. 73-80.

The sleeves 16 can also act as a medium to interface with a whole suiteof applications including the following: acting as an anchor point forelectronics (e.g., an inertial measurement unit and mechanical contactswitches); acting as an anchor point for soft sensors 26 and 30 (e.g.,may be secured via interlocking hook and loop structures, sewn together,glued together, etc.); acting as an interface to connect rigid devicesto a soft actuator body 14 (e.g., coupling to the actuator 12, via amount 32, a scoop, lever, spring, or any mechanism that needs to beactuated); integrating or embedding magnets 38 (e.g., to facilitatealignment during grasping, attaching tools 39, or to use for rapidcollection of ferrous metal objects 40), as shown in FIGS. 25-27;connecting multiple soft actuator bodies 14 in parallel, as shown inFIGS. 30 and 31, or in series (e.g., serving as X-, T-, and L-joints orend-to-end joints, as shown in FIGS. 28, 29, and 32-34), wherein thesleeves 16 can be used to create 3D structures; providing any of avariety of textures for gripping, twisting, sliding, or rolling objects(e.g., via brushes 44, a sticky surface, a bumpy surface 46, or viaattachment mechanisms, such as hooks and/or loops 48, as shown in FIGS.35-37); and routing tubing or wiring 52 through perimeter channels 50 tominimize snagging and tangling of the tubes and wires 52, as shown inFIGS. 38 and 39.

In FIGS. 83-85, a sleeve 16 that includes gripping features 49 forinterfacing with objects is shown; the sleeve 16 can also extend furtheracross the soft actuator body 14 and include apertures 22 or otherfeatures for bending or other forms of actuation, as shown in otherembodiments.

In other embodiments, as shown in FIGS. 40 and 41, connected ring-shapedsleeve 16 sections that are narrow in width and spaced appropriatelyalong a strain-limiting layer 54 can still achieve many of the interfaceapplications, described above, without significantly changing thecurling motion of the actuator 12.

The sleeves 16 can be formed of a single piece of material with cut-outsor slits 22 at different longitudinal and radial positions along andabout the sleeve 16, as shown in FIGS. 46-48, 76 and 77, definingmultiple bending positions along multiple axes and that can be used tojoin a plurality of soft actuator bodies 14, as shown in FIGS. 32-34(e.g., with multiple interconnected sleeve ends).

Shown in FIGS. 42-44, at one end of the sleeve 16 is a fixture 58attached to the soft actuator body 14 and including the pneumaticconnection 60 which provides for fluid communication between a pump 18and the chamber 20 defined by the walls of the soft actuator body 14.The range of motions of a 28A durometer sleeved soft bending actuator 12at sleeve spacings of (a) 0 mm, (b) 15 mm, and (c) 30 mm arerespectively shown for comparison in FIGS. 42-44. The shadow images 56show the actuators 12 bending at different pressures.

The sleeves 16 can be anchored to the surface of the soft actuator body14 through mechanical features on the surface of the soft actuator body14 (e.g., bumps, bellows, Kevlar ribs, other geometric locking features,etc.); and the sleeves 16 can be formed with fiber reinforcement. Thesleeves 16 can also have integrated electrical wiring 62 (as shown inFIG. 49), a circuit board 28, heating elements, cooling elements,temperature sensors, routing channels 50, capacitive sensors, forcesensors 26, strain sensors 30 and so forth.

In particular applications, the sleeves 16 can connect a soft actuatorbody 14 to a human (or other animal) body part 63, such as a finger, asshown in FIG. 50 (wherein the actuator 12 may be, e.g., 3-15 cm inlength with a thickness of, e.g., 0.5 to 2 cm), or to any other jointedbody part. In other embodiments, the sleeves 16 can connect softactuator bodies 14 to clothing.

In additional embodiments, as shown in FIGS. 52, 53, 55, 55, and 58-60,soft actuators 12 can be assembled into a manipulator body 64, wheresleeves 16 can be cut to different lengths to match (e.g., within 5%)the shape/dimensions of an object 66 to be grasped. For comparison,manipulators with sleeve-less curling soft actuator bodies 14 are shownin FIGS. 51, 54, and 57, where the curled soft actuators 12 can be seento not conform closely to the surfaces of the object 66 to bemanipulated. In the embodiments of FIGS. 54-56, an additional downwardforce is applied to the object 66 via a hook 67 extending from theobject 66. Use of the proposed sleeve 16 enables improved shape matchingto angular objects 66 and improved holding strength. In theseembodiments, sleeve length can be tuned/adjusted (e.g., by rolling,sliding, screwing/unscrewing, etc.), as shown in FIGS. 61-69, to matchthe lengths of sides of the object 66 to be manipulated; and the sleeves16 can be constructed from or combined with materials with rigid,flexible, and elastomeric properties. For example, a sleeve 16 can jointwo rigid components 54 to make a compliant joint, as shown in FIGS. 70and 71.

FIG. 70 provides a cross-sectional comparison of a fiber-reinforcedactuator 12 with and without a fiber-reinforced laminate, where (a)shows an illustrated cross section and actual side view of anunpressurized fiber-reinforced actuator 12; (b) shows expansion of theactuator walls due to fluid pressurization (note the outward bowing ofthe flat face 15); (c) demonstrates placement of the fiber-reinforcedlaminate on a fiber-reinforced actuator 12; and (d) shows an illustratedcross-sectional view of the actuator 12 when a sleeve 16 is added. Thecombination of the sleeve 16 and fiber-reinforced laminate stiffens theflat face 15 and eliminates or reduces visual indications of bowing.

FIG. 86 presents an alternative to the design of embodiment (c) in FIG.70, where instead of integrating rigid elements 54 with the sleeve 16 tostiffen portions of the actuator, vacuum jamming pouches 80 areintegrated into the sleeve 16. In this embodiment, the fluid line 60connects to a vacuum source. Contained in the vacuum jamming pouches 80are loose particles or laminate layers initially at atmosphericpressure. However, when these sections are exposed to a vacuum, thepouch walls close in on the contents, restricting their movement, andcausing a phase transition (i.e., jamming) of pouches 80 to a more rigidstate. Advantageous features of this configuration include the abilityto adjust the stiffness of a pouch 80 by adjusting the vacuum pressure,and reversibility, where the initial flexible state of the pouch 80 canbe returned by releasing the vacuum.

FIG. 87 presents a configuration of a sleeve 16, where vacuum jammingpouches 80 are placed opposite apertures 22 to actively controldeformation of the actuator 12 at the apertures 22. FIG. 88 presents anillustration of this concept where the soft actuator body 14 ispressurized; however, a portion of the soft actuator body 14 at oneaperture 22 (the furthest right) is restricted because the vacuumjamming pouch 80′ is under a vacuum making it stiffer than the otherpouch 80, which is at atmospheric pressure.

Vacuum jamming has also proven to provide effective means for grippingan object, as has been demonstrated by Cornell University and EmpireRobotics, Inc. (see, e.g. US published patent application No.20130106127 A1). To pick up an object, a vacuum jamming gripper 82, asshown in FIG. 89, with an internal pressure at atmosphere, is placed ontop of the object and conforms to it. Vacuum is applied to harden thegripper 82, which generates gripping forces through friction frompinching, entrapment, and vacuum suction. Furthermore, the object can bereleased by injecting air into the gripper 82 to release the vacuum.FIG. 89 presents a concept where a vacuum jamming gripper 82 can beintegrated with a sleeve 16 such that, depending on the task at hand,this gripping capability can be arbitrarily added to or removed from anactuator 12.

FIG. 71 illustrates the range of motion of a 28A durometer soft bendingactuator 12 with 0.8-mm-thick fiber-reinforced laminates on the flatsurface 15 of the soft actuator body 14 and with (a) 0 mm, (b) 15 mm,and (c) 30 mm spacing across the apertures 22 in the sleeves 16. A softactuator 12 with an extension segment 70 that permits localizedextension is shown in FIGS. 72 and 73. In this embodiment, the extensionis facilitated by a gap between sections of a substantially inelasticouter sleeve 16″ and an expandable inner sleeve 16′ over a soft actuatorbody 14. Where the outer sleeve 16″ is removed (producing a gap), theexposed inner sleeve 16′ can radially expand and contract with fluidflow into and out of the soft actuator 12. At the bending joints,apertures 22 can be made in both sleeves 16′ and 16″ without completelysevering the sleeves 16′ and 16″ to facilitate bending of the softactuator 12 at these locations. Furthermore, for actuators 12 thatproduce more than one type of motion (such as bending, extending,contracting, extending-twisting, and bending-twisting to name a few),the sleeve 16 can be used as a means to lock or unlock these motions.

As shown in FIGS. 74-76, the sleeve 16 includes an uncut portion 69behind the aperture 22 to provide a continuous length of sleeve materialat each of the bending/pivot locations. A linearly extending softactuator body 14 contained in a sleeve 16 with a plurality of apertures(slits) 22 configured to generate bending of the actuator about aplurality of axes with different orientations is shown in FIG. 77; and alinearly extending soft actuator body 14 converted into a bendingactuator by a sleeve 16 with a plurality of apertures 22 that share acommon orientation and consistent spacing there between is shown in FIG.78.

A power grip glove 72 including a curling soft actuator 12 for eachfinger is shown in FIGS. 79 and 80, wherein each actuator 12 includes alinearly extending soft actuator body 14 contained in a sleeve 16 havinga plurality of apertures 22 to convert the linear actuation of the softactuator body 14 to a bending/curling motion. The position of theapertures 22 can be customized to align with the location of thewearer's joints. The elasticity of the soft actuator body 14 allows theactuator 12 to extend at joints to, e.g., maintain contact (withoutslipping) with a bending finger with which the actuator 12 is incontact. In other embodiments, the actuators 12 can be incorporated intoanother type of wearable apparel, wherein the actuators 12 can beconfigured along other joints and designed to generate greater or lesserforce, as needed. Control electronics can also be incorporated into theapparel for controlling the pump 18 and thereby controlling actuation ofthe actuators 12.

In some applications, the actuator 12 can be disposable (e.g., discardedafter a specified period of use, such as after one month of use) andreplaced, while retaining the pump 18 for long-term reuse.

In other embodiments, the soft actuators 12 can be used independently(e.g., to create robotic hand) without joining the soft actuators 12 toa body part of a human or other organism. For example, a plurality ofactuators 12 can extend from a hub to form a grasper that can pick upand manipulate objects in an environment that may be inhospitable tohumans (e.g., at great depths, such as 200 meters deep or more,undersea).

In particular embodiments, the soft actuator body 14 can be provided ona reel, as shown in FIG. 81, and cut to a desired length. Using thisembodiment, soft actuators 12 can be rapidly assembled by cutting thedesired length of soft actuator body 14 from a reel and then capping theends of the resulting soft actuator bodies 14, as shown in FIG. 82. Atleast one of the end caps 68 illustrated in FIG. 82 includes an embeddedpneumatic or hydraulic connection passing there through (and to which apneumatic or hydraulic pump 18 coupled with a fluid source is connected)to allow fluid to be pumped into the soft actuator body 14 to power itsactuation; and a sleeve 16 can be fitted over the soft actuator body 14with apertures 22 to allow for bending or curving of the actuator, 12 asdesired.

In additional embodiments, the sleeve 16 can be formed of a materialthat is anisotropic to provide the actuator 12 with different properties(e.g., different strain characteristics) along different axes.Additionally, the sleeve 16 can be formed of a woven material that canthen be made rigid by coating it with an epoxy or polyurethane. Furtherstill, sleeves 16 can be applied to monolithic soft actuator bodies 14that contain a plurality of air chambers. In still more embodiments, thesleeve 16 can include an electronic sensor [e.g., electromyography(EMG)] configured to detect signals (e.g., electrical signals, muscleactivity) that accompany a human's effort to activate muscles togenerate movement, which can then be mechanically assisted by the softactuator 12 of this disclosure.

In describing embodiments of the invention, specific terminology is usedfor the sake of clarity. For the purpose of description, specific termsare intended to at least include technical and functional equivalentsthat operate in a similar manner to accomplish a similar result.Additionally, in some instances where a particular embodiment of theinvention includes a plurality of system elements or method steps, thoseelements or steps may be replaced with a single element or step;likewise, a single element or step may be replaced with a plurality ofelements or steps that serve the same purpose. Further, where parametersfor various properties or other values are specified herein forembodiments of the invention, those parameters or values can be adjustedup or down by 1/100^(th), 1/50^(th), 1/20^(th), 1/10^(th), ⅕^(th),⅓^(rd), ½, ⅔^(rd), ¾^(th), ⅘^(th), 9/10^(th), 19/20^(th), 49/50^(th),99/100^(th), etc. (or up by a factor of 1, 2, 3, 4, 5, 6, 8, 10, 20, 50,100, etc.), or by rounded-off approximations thereof, unless otherwisespecified. Moreover, while this invention has been shown and describedwith references to particular embodiments thereof, those skilled in theart will understand that various substitutions and alterations in formand details may be made therein without departing from the scope of theinvention. Further still, other aspects, functions and advantages arealso within the scope of the invention; and all embodiments of theinvention need not necessarily achieve all of the advantages or possessall of the characteristics described above. Additionally, steps,elements and features discussed herein in connection with one embodimentcan likewise be used in conjunction with other embodiments. The contentsof references, including reference texts, journal articles, patents,patent applications, etc., cited throughout the text are herebyincorporated by reference in their entirety; and appropriate components,steps, and characterizations from these references may or may not beincluded in embodiments of this invention. Still further, the componentsand steps identified in the Background section are integral to thisdisclosure and can be used in conjunction with or substituted forcomponents and steps described elsewhere in the disclosure within thescope of the invention. In method claims, where stages are recited in aparticular order—with or without sequenced prefacing characters addedfor ease of reference—the stages are not to be interpreted as beingtemporally limited to the order in which they are recited unlessotherwise specified or implied by the terms and phrasing.

What is claimed is:
 1. A mechanically programmed actuator comprising: atleast one soft actuator body configured to bend, linearly extend,contract, twist, or combinations thereof when actuated withoutconstraint; an activation mechanism configured to actuate the softactuator; and at least one sleeve wrapped around at least a part of thesoft actuator body and configured to constrain the soft actuator bodyinside the sleeve when actuated and to enable the soft actuator body todeform where the soft actuator body is not covered by the sleeve.
 2. Themechanically programmed actuator of claim 1, wherein the soft actuatorbody defines an internal chamber, and wherein the activation mechanismincludes a pump configured to pump fluid into the internal chamber todeform the soft actuator body.
 3. The mechanically programmed actuatorof claim 2, wherein the soft actuator body comprises at least onematerial that is at least one of flexible and elastomeric and that isselected from hyper-elastic silicone, thermoplastic urethane,thermoplastic elastomer, rubber, nylon, woven materials, non-wovenmaterials, elastic polyurethane, and polyethylene.
 4. The mechanicallyprogrammed actuator of claim 1, wherein the soft actuator body includesa strain-limiting layer along a side of the soft actuator body, andwherein the soft actuator body is configured to produce bending of thesoft actuator body by restricting expansion of that side of the softactuator body.
 5. The mechanically programmed actuator of claim 1, wherea plurality of sleeves are wrapped around respective parts of the softactuator body, and wherein at least one of the sleeves (a) has acomposition distinct from that of another of the sleeves and (b) hasanisotropic mechanical properties distinct from that of another of thesleeves.
 6. The mechanically programmed actuator of claim 5, wherein agap is provided between at least two of the sleeves, causing the softbody actuator to deform at the gap between the sleeves.
 7. Themechanically programmed actuator of claim 1, wherein the sleeve definesan aperture, causing the soft actuator body to deform at the aperture.8. The mechanically programmed actuator of claim 1, wherein the sleeveincludes a plurality of apertures, causing the soft actuator body todeform at the apertures.
 9. The mechanically programmed actuator ofclaim 8, wherein the apertures are defined at different longitudinal andradial positions in the sleeve.
 10. The mechanically programmed actuatorof claim 1, wherein the sleeve includes an interface selected fromelectronics, sensors, magnets, routing, and coupling mechanisms.
 11. Themechanically programmed actuator of claim 1, wherein the sleeve servesas a coupler between a plurality of the soft actuator bodies.
 12. Themechanically programmed actuator of claim 1, wherein a plurality ofsleeves are coupled together and contain parts of respective softactuator bodies.
 13. The mechanically programmed actuator of claim 1,wherein the sleeve is configured to have an adjustable length to alterthe amount of the soft actuator body contained by the sleeve.
 14. Themechanically programmed actuator of claim 1, wherein at least a portionof the sleeve is made rigid with a hardening material or agent.
 15. Themechanically programmed actuator of claim 1, wherein the sleeve securesrigid parts to the actuator body.
 16. The mechanically programmedactuator of claim 1, wherein the sleeve is removable.
 17. Themechanically programmed actuator of claim 1, wherein at least oneelement having a stiffness greater than the soft actuator body is placedon or inside the sleeve so as to further control deformation of the softactuator body.
 18. The mechanically programmed actuator of claim 1,wherein the actuator includes inner and outer sleeves concentricallywrapped around the soft actuator body, wherein gaps or apertures areprovided at the outer sleeves, exposing a portion of the inner sleeve.19. A method for mechanical actuation, comprising: using a mechanicallyprogrammed actuator including at least one soft actuator body thatdefines a chamber and at least one sleeve wrapped around part of thesoft actuator body; and pumping fluid into the chamber defined by thesoft actuator body, causing the soft actuator body to deform where thesoft actuator body is not covered by the sleeve, while the sleeve limitsthe soft actuator body from deforming where the sleeve covers the softactuator body.
 20. The method of claim 19, wherein the actuator includesat least two soft actuator bodies, each with at least one sleeve wrappedaround part of each soft actuator body.
 21. The method of claim 20,further comprising actuating the soft actuator bodies to grasp an objectbetween the soft actuator bodies.